The correct URL for your blog is:
http://hlinstitute.wordpress.com - there is no "www" in it
There are two sets of social bookmarks available for use on wordpress.com blogs that you can manually add to your posts. There is no automatic bookmarking at wordpress.com. Using them will also update your twitter account as well when you publish a post. They are:
The blog you point to is not a wordpress.COM blog and there are significant software differences between wordpress.com software and wordpress.org software. We cannot use "share it" on wordpress.com blogs. In fact, wordpress.com blogs do not have FTP access and plugins.